The present invention relates to a method and apparatus for joining two thread ends by splicing.
The joining of thread ends by splicing has largely displaced the previously widely used knotting of the thread ends, because splicing leads to connections differing little from the remaining thread as regards strength and shape.
Different apparatuses for producing splices are known, U.S. Pat. No. 4,263,775 disclosing an apparatus representing most of the known constructions. In this apparatus, in the case of a thread break, the thread ends are received by suction nozzles and brought into the vicinity of a splicing device, which has a splicing chamber subject to the action of compressed air. However, in order to provide a clean splice, the thread ends must be cut clean by cutting devices. The cut ends are then sucked into the thread end preparation tube subject to suction pressure. One such preparation tube is required for each thread end. In said preparation tubes, the thread ends are untwisted by a compressed air flow and loose thread portions are removed. After thread end preparation, the thread end are retracted or drawn back to such an extent that they are located in or alongside the splicing chamber and this is followed by the splicing of the thread ends by supplying compressed air to the splicing chamber. It is necessary for such splicing that one thread end is inserted into the chamber from one side of a splicing device and the other thread end is inserted from the other side of the device. It must be borne in mind that this construction, in which a single preparation tube is associated with each thread end, constitutes a relatively complicated solution, because such preparation tube must be controlled in such a way that initially a suction flow and then, for the actual thread end preparation, a pressure flow is produced.
The present invention provides a method of apparatus for joining two thread ends by splicing in such a way that the manufacturing effort and expenditure is reduced and also so that there is improved reliability concerning thread end preparation, while obtaining a splice with the same quality as with the known methods and apparatuses.